Temperature-indicating device.



M. S. OLAWSON.

TEMPERATURE INDIGATING DEVICE.

APPLICATION FILED MAY 31, 1910.

Patented Apr. 28, 1914 anve/wllqz apparatus for detecting the changes of tem-' ITNITED STATES PATENT. OFFICE.

MONROE S. CLAWSON, OF. NEW YORK, N.

. TEMPERATUBE-INDICATING DEVICE.

Specification of Letters Patent.

Application filed-May 31, 1910. Serial No. 564,298.

cating the temperature of furnaces, retorts' and thelike and refers particularly to an perature in retorts used with my improvement in oxygen generators for which Letters Patent'iNor 964,492, were issued to me on July 19, 1910.

The object of' my invention isthe improvement of means for detecting changes of temperature in the retort consisting in securing a bar of metal thereto widely difiering from the metal of the retort in the thermoelectric series, and connecting said bar to one pole of a galvanometer, while the other pole of the galvanometer isconnected to a pipe or other metal structure secured to the retort and at a distance therefrom so as not to be influenced by the heat of the retort. v 1

My invention will be described in detail hereinafter and illustrated in I the accompanying drawings in which a Figure 1 is a side view showing a retort such as used inmy oxygen generator apparatus and showing my temperature indicating device applied thereto, Fig. 2, a top plan view, and Fig. 3, a sectional view of a retort showing a modified form of thermoile. I p In the drawing similar reference characters indicate corresponding parts in all of the views.

The retort 1 is constructed of any desired metal such for instance as iron and has a pipe 2 tapped into it which as stated in the U. S. Patent #964,492, above referred to,-1s provided to convey ozone from a suitable generator, not shown, to the retort.

As in .oxygen generation it is important to know the exact temperature of the retort at all times I provide a'temperature indicating device employing the, principles of thermoelectricity in which 3 indicates a galvanometer of standard type having 1ts positive side connected by means of a wire 4with a thermopile of which one electrode consists of a retort 1 and the other electrode ofla bar 5 of any metal having a thermoelectrical difference with the retort, as, for example, the.

retort being of iron the bar 5'could be made of German silver. The end of the bar 5 where secured to retort 1 is preferably made wider as shown at 6, and welded or otherwise secured to the retort opposite its middle so that the 'gal'vanometer' will at all times register the mean temperature of the retort. The negative side of the-galvanometer 3 is connected by Wire 7. with pipe or tube 2 at a point remote from' retort 1 so that the heat thereof will not reach it and set up a'counter electro-motive force action.

In Fig. 3 is illustrated a modified form of thermopile in which the retort 11 .is formed with an opening. 12 in its side to re- Patented Apr. 28, 1914.

ceive a tube 13 of' iron or other metal, having a plug 14, in its inner end, of-German silver or other metal differing from the metal of the tube in the thermoelectric series, and securing thereto the wire 15 connected to the positive side of the galvanometer.

I have shown and described a retort such as used in generating oxygen but it will be apparent that it is adapted to other forms of retorts and furnaces so that I donot limit myself to the structure shown and described nor to the metalsstated in the thermopile as other metals may be employed 'without altering the spirit of my invention. It will also be apparent that in retorts not employing a pipe 2 as well as in retorts employing the pipe I may make the negative side of the galvanometerin contact with some othermetallic appendage of the retort, such a structure being readily apparent to any person either skilled or unskilled and considered to be not'necessary to be illustrated.

nected with the positive side of the galvanometer, and the negative side of the galvanometer being connected with the pipe aforesaid at apoint remote from the retort.

2. A temperature indicating device, comprising .in combination. ametal retort, a

constitutes a thermopile, said bar being conpipe tapped into the retort, a galvanometer, a bar of metal having a difl'erent thermoelectric potential from the metal of the retort, and secured thereto, thus forming an electrode, which with the retort as the other electrode constitutes a thermopile, there being means whereby said bar of met-a1 is connected with one terminal of the galvanometer and the other terminal of the galvanometer is connected with the aforesaid pipe at a point remote from the retort.

3. A'temperature indicating device comprising-a thermopile one element of which is a retort, and the other element of which is a metal bar secured to the retort and having a different thermo-eleotric potential therefrom, said metal bar being provided with aID enlarged body portion for attachment with' H. D. ABBOrr, C. Lornz on VICTORIA. Y 

